Stacked caseless heat exchangers



March 15, 1966 ARMES 3,240,268

STACKED CASELESS HEAT EXCHANGERS Filed Jan. 2, 1962 INVENTOR. fieafl@rmes ATTORNEY United States Patent 3,240,268 STACKED CASELESS HEATEXCHANGERS Fred D. Armes, Lockport, N.Y., assignor to General MotorsCorporation, Detroit, Mich., a corporation of Delaware Filed Jan. 2,1962, Ser. No. 163,416 2 Claims. (Cl. 165167) This invention relates toheat exchangers and more particularly to liquid-to-liquid heatexchangers of the stacked metal plate type.

When providing stacked plate heat exchangers, it has been customary touse a casing, not only for supporting purposes with respect to theadjoining elements, but also to prevent outward deformation of theplates as the latter are internally subjected to fluid pressures. Italso has been customary heretofore to use added sealing devices, such asgaskets or packing, between adjacent plates of the stack to preventleakage therefrom.

An object of the present invention is to provide an improvedliquid-to-liquid, stacked plate-type heat exchanger in which no casingor added sealing devices are required.

A feature of the present invention is a multiple plate heat exchanger inwhich the plates are such that they themselves form junctions sealing orcontaining liquids to be conducted between the plates in heat exchangerelation. Another feature is a stacked plate heat exchanger which hasplates of uniform thicknesses and which plates are self-constrainingagainst the tendency to deform because of the application of internalfluid pressure.

These and other important features of the invention will now bedescribed in detail in the specification and then pointed out moreparticularly in the appended claims.

In the drawings:

FIGURE 1 is a perspective view of a two-liquid heat exchanger presentingone embodiment of the present invention;

FIGURE 2 is a cross-sectional view looking in the direction of thearrows 22 in one plane in FIGURE 1 and drawn to a larger scale; and

FIGURE 3 is a view similar to that of FIGURE 2 but looking in thedirection of the arrows 33 in another plane in FIGURE 1.

In the drawings, the heat exchanger is shown as constituting a stack ofthin metal or aluminum plates, the stack being generally indicated at10. At each end of the stack are two heavy plates 12 and 14 and one thinplate 16 or 18, and between the ends are eighteen (18) intermediateplates 20. The number of intermediate plates 20 may be varied to suitrequirements of the exchanger.

Each of the thin metal plates 16, 18 and 20 is formed with flatperipheral flanges or margins 22 and two openings 24 and 26 as well astwo openings 28 and 30. The openings 24 and 28 are formed near one endof each plate, and the openings 26 and 30 are located near the other endof each plate. Each plate bears oblique corrugations 32 which are at anangle to the longitudinal dimension of the stack. As seen in FIGURE 1,the alternate thin plates have their corrugations 32 such that theridges of one plate are transverse to and in contact with the ridges ofthe next plate. The openings 24 form a series of openings preferably inregistry through the stack thereby establishing communication betweenchambers A as each is defined between adjacent plates. The openings 26also preferably, but not necessarily, are in registry as shown in FIGURE3, thereby connecting the chambers A at the other end of the stack anddiagonally opposite the openings 24. The aligned openings 28 and 30 giveintercommunication between chambers B formed by the plates and atdiagonally opposite corner zones of 'ice such chambers, and FIGURES 2and 3 clearly show that the chambers A alternate with the chambers Balong the thickness dimension of the stack. It is to be noted that thethin metal margins defining the openings 24 and 26 are in planes oflsetfrom the planes of the margins of openings 28 and 30. The thick endplate 14 is provided with two openings 42 and 44, whereas the heavyupper plate 12 at the other end of the stack is provided with twoopenings 46 and 50. The openings 42, 44, 46, and 50 are fitted withinlet and outlet conduits 42, 44', 46 and 50, respectively. Each isfastened to its supporting plate by welding or soldering as at 52.

The conduit 42' serves as the inlet conduit supplying one fluid to thechambers A, and the conduit 50' serves as a discharge conduit for thosechambers. The conduit 46 serves as an inlet for a second fluid to beintroduced to the chambers B, and the discharge from these chambers isby way of the conduit 44.

In the particular embodiment shown, the two thin end plates 16 and 18have spacing rings 60 serving to brace them at the periphery of each ofthe corresponding plate openings 28 and 30. With the aid of the thickoutside plates, these rings 60 are not necessary and could be elminatedby appropriately forming the heavy plates so that they are integraltherewith.

From the above, it will be seen that a casing is not necessary for thestack of plates once they are soldered or brazed together to form aunitary and homogeneous structure exhibiting an unbroken wall extendingaround the stack and from one end to the other of the latter. Thedirection of flow of the fluids is shown as indicated by the arrows inFIGURE 1, as countercurrent flow is preferred; but it will be understoodthat parallel current flow also is possible with the structure given.One liquid is conducted through chambers A, and the second liquid isconducted through the chambers B which alternate with the chambers A.The turbulent flow of each fluid through its respective flow passage isconductive to eflective heat interchange between the liquids, theturbulence being due to the corrugations which may be of various shapes,sizes, and also angles as measured with respect to the longitudinaldimension of the stack.

What is claimed is:

1. A heat exchanger for conducting two liquids in heat exchangerelation, said exchanger comprising a stack of plates formingsuccessively arranged flow chambers, said plates including two endplates at each end of said stack and corrugated intermediate plates,each of said intermediate plates having its corrugations extendingtransverse to and being in contact with the corrugations in an adjacentplate and its periphery joined to the periphery of said adjacent plateto form one of said flow chambers, said intermediate plates having fourcontinuous flanges defining four flow openings, two of the continuousflanges of each intermediate plate being joined to and in registry withtwo continuous flanges of an adjacent intermediate plate givingcontinuity of communication within one set of said flow chambers as afirst flow passage for one fluid, the other two continuous flanges ofeach intermediate plate being joined to and in registry with the othertwo continuous flanges of an adjacent plate giving continuity ofcommunication within a second set of flow chambers alternating with thesaid one set of flow chambers as a flow passage for a second fluid, aninlet and an outlet leading to each of the first and second fluid flowpassages whereby said fluids may be passed in heat exchange relationalong opposite sides of each of said intermediate plates, and said stackforming an unbroken wall extending around its peripheral extent.

2. A heat exchanger comprising a stack of thin metal plates brazedtogether, each of said plates being of uniform thickness, some of saidplates being intermediate plates within the stack, each of saidintermediate plates having corrugations, peripheral margins and alsoopenings defined by flanges, said corrugations extending from saidmargins and terminating short of said openings, each of saidcorrugations in said intermediate plates being at a substantial anglewith and in contact with the corrugations of an adjacent plate, saidperipheral margins and opening flanges being brazed together to form twosets of flow chambers, the stack presenting a homogeneous structure inwhich flow chambers of one set alternate with the flow chambers of theother set, means for admitting a separate fluid to each of said sets andat opposite ends of said exchanger, means for discharging a fluid fromeach of said sets at opposite ends of the exchanger, and saidintermediate plates presenting a solid wall extending around the saidstack and from one end to the other end of the latter.

References Cited by the Examiner UNITED STATES PATENTS 800,977 10/1905Brewtnall 1b5167 1,966,133 7/1934 Pieper 165-166 2,064,931 12/1936Lysholm 165166 2,251,066 7/1941 Persson et al. 165-167 2,392,444 1/1946Amand et al 165167 2,596,008 5/1952 Collins 165167 2,617,634 11/1952Jendrassik 165167 ROBERT A. OLEARY, Primary Examiner.

1. A HEAT EXCHANGER FOR CONDUCTING TWO LIQUIDS IN HEAT EXCHANGERELATION, SAID EXCHANGER COMPRISING A STACK OF PLATES FORMINGSUCCESSIVELY ARRANGED FLOW CHAMBERS, SAID PLATES INCLUDING TWO ENDPLATES AT EACH OF SAID STACK AND CORRUGATGED INTERMEDIATE PLATES, EACHOF SAID INTERMEDIATE PLATES HAVING ITS CORRUGATIONS EXTENDING TRANSVERSETO AND BEING IN CONTACT WITH THE CORRUGATIONS IN AN ADJACENT PLATE ANDITS PERIPHERY JOINED TO THE PERIPHERY OF SAID ADJACENT PLATE TO FORM ONEOF SAID FLOW CHAMBERS, SAID INTERMEDIATE PLATES HAVING FOUR CONTINUOUSFLANGES DEFINING FOUR FLOW OPENINGS, TWO OF THE CONTINUOUS FLANGES OFEACH INTERMEDIATE PLATE BEING JOINED TO AND IN REGISTRY WITH TWOCONTINUOUS FLANGES OF AN ADJACENT INTERMEDIATE PLATE GIVING CONTINUITYOF COMMUNICATION WITHIN ONE SET OF SAID FLOW CHAMBERS AS A FIRST FLOWPASSAGE FOR ONE